Shellfish aquaculture in the City of Carlsbad‘s Agua Hedionda Lagoon began as a California Sea Grant research project by San Diego State University in the 1960’s. Their research determined which shellfish species were best suited to grow in the lagoon, which, at the time had been reconnected with the Pacific Ocean. Their research concluded the lagoon was ideal for growing shellfish and that the lagoon’s long-term health would benefit from the biofiltration eco-services provided by millions of shellfish. Soon thereafter the scientists joined forces with shellfish farmers to establish the Carlsbad Aquafarm and start growing shellfish.

Carlsbad Aquafarm is grateful for the support it receives from NRG Energy, which owns and operates the Encina Power Station and provides stewardship of the Agua Hedionda Lagoon. NRG has long recognized the ecological importance of the Carlsbad Aquafarm and its brand value to Carlsbad as a “Working Waterfront” and place people earn a living by sustainably working in harmony with the sea.

Aquaculture research has continued for over 60 years and now includes the USC’s Wrigley Marine Labs (Selective breeding of Pacific Oysters for resiliency in a changing ocean ), San Diego State University, Aquaculture Training), UCSD, SIO and Southern California Coast Ocean Observatory (Ocean Acidification), California State University Fullerton (Living Shoreline Restoration with Native Oysters Eelgrass) and the UC Davis Bodega Marine Lab (Abalone Research and Population Restoration).

Agua Hedionda Lagoon Commercial Aquaculture is celebrating its 50th Anniversary. However, harvesting shellfish in the area began over 13,500 years ago when the New World’s first people made their maiden journey down the west coast, fishing, and beachcombing for shellfish in the region’s coastal lagoon.

Agua Hedionda Lagoon - History

For tens of thousands of years a complex of coastal wetlands extending from Santa Barbara to San Diego has been part of the Pacific Flyway, one of four continental routes where migratory water birds and shorebirds have taken wing from breeding grounds in northern latitudes to southern wintering grounds.

The lagoons of North San Diego County estuarine complex are composed of vegetated salt marshes, unvegetated salt and mud flats, and subtidal waters. The southern portion of the complex extends southward from Oceanside to Ensenada has been inhabited by the first peoples of the New World for thousands of years. At the time of the first contact with the Spanish, the native population in San Diego County was estimated to be about 30,000, made up of five major tribes, the Luiseno, Cahuilla, Cupeno, Kumeyaay, and Diegueño. These peoples lived in semi-permanent villages, foraging for shellfish, seaweeds, as well as fishing, and hunting small game.

When the Spaniards began establishing ranches, farms and missions, they brought non-native plants, horses, cattle, goats, sheep, pigs and chickens. These invasive plants and livestock began to degrade native ecosystem systems. Prior to Spanish colonization, the Agua Hedionda Lagoon was a healthy coastal estuary. Livestock runoff flowing into the lagoon’s eroded its long-standing circulation with the Pacific Ocean. The lagoon’s character changed and original Spanish name given to the lagoon, “San Simon Lipnica,” was changed to “Agua Hedionda,” which translates to stinking, pestilent waters. The lagoon has been transformed into a silty, shallow breeding ground for mosquitoes and mud flat. The once verdant marsh reeds and clear lagoon waters teeming with wildlife had become a stagnant pool, clogged with thick algal blooms. The wildlife fish and shellfish that native peoples had relied on for centuries were decimated and lands degraded to where native peoples no longer could continue their traditional way of life.

Successive waves of land owners continued to transform the California’s southern coastal landscape, bringing more waves of new settlers, roads, and eventually the railroad in 1885. Soon the town of Carlsbad was founded in 1887, and grew from a Santé Fe Railroad whistle stop, to eventually become an attractive, seaside destination. In 1952 Carlsbad was incorporated as a city to avoid annexation by Oceanside.

After Carlsbad’s corporation as a city, SDGE purchased the Agua Hedionda Lagoon and surrounding lands for the purpose of restoring the lagoon’s connection with the Pacific and using seawater to cool its electrical power generators that were being built to serve Carlsbad’s rapidly growing population. The lagoon’s was dredged in 1952, permanently reopening ocean circulation to supply cooling waters for SDGE’s Power Plant, built on the south side of the lagoon. Sand from littoral drift enters the lagoon at the rate of more than 100,000 cubic yards per year and has been removed at two-year intervals to maintain the cooling water basin of the outer lagoon.

Agua Hedionda Lagoon, a shallow pool closed to the Pacific at low tide since early European settlement, was dredged and reopened to a continuous tidal flow to cool SDGE’s Encina Power Station, constructed in 1954. Lagoon health improved and the impaired body of water became home to Great Blue herons, Brown Pelicans, Ibises, Snowy Egrets, Western Grebes, Double-crested Cormorants, Ospreys, and many other species of birds, Coyote, Fox, Bobcats, Rabbits and other mammals, amphibians, lizards and snakes, Olympia Oysters, Rock Scallops, Clams, Cockles, Sea Stars, Sea Urchins and host marine invertebrates. Other wild visitors to the restored lagoon include Dolphins, Harbor Seals, Sea Lions and Sea Turtles.

After Agua Hedionda Lagoon’s circulation was restored, scientists from San Diego State University, later joined by shellfish farmers, began growing shellfish in the lagoon. Since then billions of shellfish have been grown in the lagoon, filtering its waters, keeping the waters healthy and clear, allowing the lagoon’s Eelgrass beds to expand and its amazing diversity of wildlife to recover and flourish.